Shaft and bearing cooling means



-April 6, 1948. w. H. DAILEY, JR, ETAL SHAFT AND BEARING COOLING MEANS Filed Feb. 25, 1946 2 Sheets-Sheet 1 INVENTORS. Iva/AMA. M/ZEK/E am [an 4P0 4 flZ/VU6CZ,

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April 6, 1948.

SHAFT AND BEARING COOLING MEANS Filed ,Feb. 25, 1946 2 Sheets-Sheet 2 INYENTORSZ W/zz/nM' H. 04/4002 am fan 4P0 4 DZ/VZ/(Cf,

milk ATTORNEY.

. H. DAILEY, JR. ETAL 2,439,127

Patented Apr. 6, 1948 2339,12: SHAFT am) assume coouno mums William H. Bailey, In, Library. and Edward A.

Di Nucci, Pittsburgh, Pa., minors to Carnegie-Illinois Steel Corporation, a corporation of New Jersey Application February 25, 1946, Serial No. esomz While not limited thereto, our invention is peculiarly well suited for cooling the fan shaft and bearing of an annealing furnace such as used in the annealing of coils of steel strip.

One object of the invention is to provide means for air cooling a shaft having a portion subject to intense furnace heat.

Another object is to provide means for air cooling a bearing for a shaft operating in an intensely hot environment.

A further object is to construct and arrange the several parts herein shown and described so that they individually and collectively perform the functions set forth.

For a more complete understanding of the invention, reference should be made to the following disclosure, the accompanying drawings, and the appended claims.

In the drawings:

Figure 1 is a view in vertical longitudinal section of an annealing furnace embodying the invention.

Figure 2 is an enlarged longitudinal section illustrating the structural details of the chief component parts of the herein claimed invention,

Figure 3 is a horizontal section on lin IIIIII of Figure 2.

Figure 4 is a detail view of a sleeve shown in Figure2.

Referring in detail to the embodiment of the invention illustrated, reference numeral 10 represents a suitable base including supporting beams or rails i2, a plate- M, and a pedestal iii. The base includes a ring iii and locating pins 20 which are adapted to engage lugs 22 to position the removable furnace cover 24. The cover cmprises an outer shell 26 and an inner shell 28 with a filling or insulation 30 between them.

The furnace illustrated is of a type suited for the annealing of coils 32 of steel strip which are stacked in a pile with separators 34 between them to facilitate circulation of a gaseous atmosphere. Coil annealing furnaces of the type shown employ a'heating means capable of raising the stack -of steel coils from room temperature of about 70 F. to an annealing temperature of about 1450 F. In the furnaceshown, the heating means includes coils of radiant heating tubes 36 supported by hangers 38 depending from the furnace top 40. The specific heating means is not claimed herein, and thus need not be further described except to mention that it is desirable to provide a fan 42 to circulate a suitable deoxidizing 3 Claims. (01. 280-209) gasin contact with the coils of steel strip stacked in the furnace.

A particular feature of the present invention relates to the means for cooling the shaft N and the bearing it adjacent the heating means. The other bearing l. remote from the heating means need not be equipped with the special cooling structure, since the effectiveness of the cooling means to now be described in connection with the bearing 48 will'suiiice to maintain satisfactory operating conditions.

The bearings 46 and 48 are bolted to an upright plate 50 which is secured to the top frame structure 62 of the furnace in net.

Since the bearing 46 nearest the heating means is the one principally affected by heat transfer along the fan shaft, we provide special means for cooling the shaft in the vicinity of this bearing, and also provide a special type of sleeve 54 such as best shown in Figures 2 and 3, to retard the transfer of heat from the shaft to the adjacent parts of the bearing.

The sleeve 54 is formed of a metal having a low rate of heat conductivity, such as stainless steel. The interior of the sleeve is bored as shown in Figure 4, to provide spaced bearing portions I6 and 58 of limited area contacting the fan shaft M. These bearing portions are separated by an annular chambered portion 60 which provides for an insulating blanket of air surrounding the shaft between the bearing portions, thus serving to inhibit heat transfer. The exterior of the sleeve 54 is formed with an annular depression 62 so as to restrict the contact with the antifriction bearing raceway bushing 64 to two spaced annular areas 66 and 68 and thus negative the tendency to conduct heat from one another. The roller bearing 46 includes the antifriction rollers Iii, race rings 12 and retainer member I4 and oil seals 15 of usual or known conventional form,

any suitable man- A plurality of grooves I6 extend longitudinally on the exterior of the sleeve from the top thereof to a point beyond the lower end of the bushing 84. At the top of the sleeve, a series of annular grooves are cut so as to form the cooling fins 18. A casing .80 surrounds and encloses the upper end of the sleeve, and nozzles 82 are connected to pipes 84 leading to a supply of compressed air. Cooling air elected from the nozzles is impinged on the fins II and a slight pressure is maintained within the casing 80. Thus a plurality of streams of cooling air flow longitudinally a 3 along the exterior of atmosphere beyond the lower end or the hearing bushing 84, as suggested by the arrows in Figure 2. At the top of'the furnace is a stuffing the sleeve and exhaust to to, and means for air cooling the latter bearing and a substantial length of the shaft in the region thereof comprising a sleeve secured to the shaft havingannular portions firmly contactin the shaft and separated by an inner annular chambered portion clearing the shaft, said latter bearing having a race-bushing seated on spaced annular areas on the exterior of said sleeve, the

. exterior of the sleeve having an outer annular Deoxidizing gas is introduced intothe furnace from an inlet pipe I connected to the stuffing I box 86, and the gas circulates through the space between the sleeve and the stufilng box and enters the top of'the furnace through the clearance space I02 between the shaft 44 and the wall of the shaft opening in the furnace top.

While we have disclosed specific details of a preferred construction which an actual reduction to practice has demonstrated to be highly desirable, it is not to be'construed that we are limited thereto, since various modifications may be made by those skilled in the ar without departure from the invention as appended claims.

We claim:

1. Ina furnace having a fan therein supported on a shaft a portion of which is subjected to intense furnace heat, a bearing for said shaft and means for cooling it and an adjacent portion of the shaft comprising a sleeve secured to the shaft having respective annular portions firmly contacting the shaft and separated by an inner chambered portion clearing the shaftgan antifrlctlon liearing-race-bushing surrounding a portion of said sleeve and firmly contacting it at spaced portions and clearing it therebetween, the sleeve having a plurality of longitudinal grooves formed on its exterior and extending beyond the ends of said bushing, a casing surrounding one end of said sleeve forming an air chamber, and means effective to deliver cooling air under pressure to said chamber and force it' through the grooves insaid sleeve.

2. In an annealing furnace having a heating defined in n the 5 chambered portion between said spaced annular areas, a series of longitudinal grooves formed on the exterior of said sleeve and extendingbeyond the ends of said bushing, and means for forcing cooling air through said grooves.

3. In an annealing furnace having a heating means, aim for circulating a gaseous medium heated thereby, a shaft to which the fan is secured having one bearing remote from the heating means and anotherbearing adjacent thereto, and means for air cooling the latter bearing and a substantial length of the shaft in the region thereof comprising a sleeve secured to the shaft having annular portions firmly contacting the shaft and separated by an inner annular chambered portion clearing the shaft, saidlatter bearing having a race-bushing seated on the exterior of said sleeve, a series of longitudinal grooves formed on the exterior of said sleeve and extending beyond the ends of said race-bushing, a series of annular fins at the end of the sleeve remote from said heating means, a casing enclosing said fins. and nozzles connected with a source of air under pressure extending into said casing and adapted to direct cooling air against said fins and through said grooves.

WILLIAM H. DAILEY, JR. EDWARD A. DI NUCCI.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 2,281,971 Goddard May 5, 1942 t FOREIGN PATENTS Number Country Date France June 13, 1938 

